{"id":1745,"date":"2025-02-16T09:14:45","date_gmt":"2025-02-16T01:14:45","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=1745"},"modified":"2025-02-16T09:14:45","modified_gmt":"2025-02-16T01:14:45","slug":"sql-now-%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/02\/16\/sql-now-%e5%87%bd%e6%95%b0\/","title":{"rendered":"SQL\u00a0 NOW()\u00a0\u51fd\u6570"},"content":{"rendered":"\n

NOW()<\/code> \u662f SQL \u4e2d\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u7528\u4e8e\u8fd4\u56de\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002\u8be5\u51fd\u6570\u901a\u5e38\u7528\u4e8e\u8bb0\u5f55\u6570\u636e\u63d2\u5165\u6216\u66f4\u65b0\u65f6\u7684\u65f6\u95f4\u6233\uff0c\u6216\u8005\u5728\u67e5\u8be2\u4e2d\u8fdb\u884c\u65e5\u671f\u65f6\u95f4\u7684\u64cd\u4f5c\u3002<\/p>\n\n\n\n

1. NOW()<\/code> \u7684\u57fa\u672c\u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
NOW();<\/code><\/pre>\n\n\n\n
NOW()<\/code> \u65e0\u9700\u4efb\u4f55\u53c2\u6570\uff0c\u5b83\u4f1a\u8fd4\u56de\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u683c\u5f0f\u901a\u5e38\u4e3a YYYY-MM-DD HH:MM:SS<\/code>\u3002<\/p>\n\n\n\n
2. NOW()<\/code> \u7684\u793a\u4f8b<\/strong><\/h3>\n\n\n\n
\u5047\u8bbe\u4f60\u6709\u4e00\u4e2a\u540d\u4e3a orders<\/code> \u7684\u8868\uff0c\u8bb0\u5f55\u8ba2\u5355\u4fe1\u606f\uff0c\u8868\u7ed3\u6784\u5982\u4e0b\uff1a<\/p>\n\n\n\n
order_id<\/th>customer_name<\/th>order_date<\/th><\/tr><\/thead>
1<\/td>Alice<\/td>2025-02-16 10:30:00<\/td><\/tr>
2<\/td>Bob<\/td>2025-02-16 14:45:00<\/td><\/tr>
3<\/td>Charlie<\/td>2025-02-16 17:00:00<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
2.1 \u83b7\u53d6\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4<\/strong><\/h4>\n\n\n\n
\u4f60\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528 NOW()<\/code> \u51fd\u6570\u6765\u83b7\u53d6\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\uff1a<\/p>\n\n\n\n
SELECT NOW() AS current_datetime;<\/code><\/pre>\n\n\n\n
\u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
current_datetime<\/th><\/tr><\/thead>
2025-02-16 17:10:35<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u8fd9\u91cc\uff0cNOW()<\/code> \u8fd4\u56de\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u683c\u5f0f\u4e3a YYYY-MM-DD HH:MM:SS<\/code>\u3002<\/p>\n\n\n\n
2.2 \u8bb0\u5f55\u5f53\u524d\u65f6\u95f4<\/strong><\/h4>\n\n\n\n
\u5728\u63d2\u5165\u6570\u636e\u65f6\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528 NOW()<\/code> \u6765\u8bb0\u5f55\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002\u4f8b\u5982\uff0c\u5f53\u6dfb\u52a0\u65b0\u8ba2\u5355\u65f6\uff1a<\/p>\n\n\n\n
INSERT INTO orders (customer_name, order_date)\nVALUES ('David', NOW());<\/code><\/pre>\n\n\n\n
\u8fd9\u5c06\u63d2\u5165\u4e00\u6761\u65b0\u8bb0\u5f55\uff0c\u5e76\u5c06\u5f53\u524d\u65f6\u95f4\u4f5c\u4e3a order_date<\/code> \u5b57\u6bb5\u7684\u503c\u3002<\/p>\n\n\n\n
2.3 \u4e0e\u65e5\u671f\u8fdb\u884c\u6bd4\u8f83<\/strong><\/h4>\n\n\n\n
\u4f60\u53ef\u4ee5\u4f7f\u7528 NOW()<\/code> \u51fd\u6570\u6765\u4e0e\u8868\u4e2d\u7684\u65e5\u671f\u8fdb\u884c\u6bd4\u8f83\u3002\u4f8b\u5982\uff0c\u67e5\u8be2\u6240\u6709\u4eca\u5929\u4e0b\u5355\u7684\u8ba2\u5355\uff1a<\/p>\n\n\n\n
SELECT order_id, customer_name, order_date\nFROM orders\nWHERE DATE(order_date) = CURDATE();<\/code><\/pre>\n\n\n\n
\u8fd9\u91cc\uff0cCURDATE()<\/code> \u8fd4\u56de\u5f53\u524d\u65e5\u671f\uff0c\u800c DATE(order_date)<\/code> \u63d0\u53d6 order_date<\/code> \u7684\u65e5\u671f\u90e8\u5206\u3002NOW()<\/code> \u53ef\u7528\u4e8e\u4e0e\u5177\u4f53\u65f6\u95f4\u8fdb\u884c\u6bd4\u8f83\u3002<\/p>\n\n\n\n
3. NOW()<\/code> \u51fd\u6570\u5e38\u89c1\u95ee\u9898\u53ca\u89e3\u51b3\u65b9\u6848<\/strong><\/h3>\n\n\n\n
3.1 \u65f6\u533a\u5dee\u5f02<\/strong><\/h4>\n\n\n\n
NOW()<\/code> \u8fd4\u56de\u7684\u65f6\u95f4\u662f\u57fa\u4e8e\u670d\u52a1\u5668\u7684\u65f6\u533a\u8bbe\u7f6e\u3002\u5982\u679c\u4f60\u5728\u4e0d\u540c\u7684\u5730\u533a\u6216\u65f6\u533a\u4f7f\u7528\u6570\u636e\u5e93\uff0c\u8fd4\u56de\u7684\u65f6\u95f4\u53ef\u80fd\u4e0e\u672c\u5730\u65f6\u95f4\u6709\u6240\u4e0d\u540c\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u65b9\u6cd5\u5904\u7406\u65f6\u533a\u5dee\u5f02\uff1a<\/p>\n\n\n\n
    \n
  • \u5728 SQL \u67e5\u8be2\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528 CONVERT_TZ()<\/code> \u51fd\u6570\u6765\u8f6c\u6362\u65f6\u533a\uff1a<\/li>\n<\/ul>\n\n\n\n
      SELECT CONVERT_TZ(NOW(), 'UTC', 'Asia\/Shanghai') AS current_time_shanghai;<\/code><\/pre>\n\n\n\n
    \u8fd9\u5c06\u628a UTC \u65f6\u95f4\u8f6c\u6362\u4e3a\u4e0a\u6d77\u65f6\u533a\u7684\u65f6\u95f4\u3002<\/p>\n\n\n\n
    3.2 NOW()<\/code> \u4e0e CURRENT_TIMESTAMP<\/code><\/strong><\/h4>\n\n\n\n
    \u5728\u8bb8\u591a\u6570\u636e\u5e93\u4e2d\uff0cNOW()<\/code> \u548c CURRENT_TIMESTAMP<\/code> \u90fd\u8fd4\u56de\u76f8\u540c\u7684\u7ed3\u679c\u3002\u4e24\u8005\u90fd\u53ef\u4ee5\u7528\u6765\u83b7\u53d6\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002\u5b83\u4eec\u4e4b\u95f4\u7684\u5dee\u5f02\u901a\u5e38\u5f88\u5c0f\uff0c\u5177\u4f53\u53d6\u51b3\u4e8e\u6570\u636e\u5e93\u7cfb\u7edf\u3002<\/p>\n\n\n\n
    \u4f8b\u5982\uff1a<\/p>\n\n\n\n
    SELECT NOW() AS now_time, CURRENT_TIMESTAMP AS timestamp_time;<\/code><\/pre>\n\n\n\n
    \u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0cNOW()<\/code> \u548c CURRENT_TIMESTAMP<\/code> \u662f\u7b49\u6548\u7684\uff0c\u4f46\u67d0\u4e9b\u6570\u636e\u5e93\u7cfb\u7edf\u53ef\u80fd\u4f1a\u5728\u8bed\u6cd5\u6216\u5b9e\u73b0\u4e0a\u6709\u6240\u4e0d\u540c\u3002<\/p>\n\n\n\n
    3.3 \u8fd4\u56de\u7684\u683c\u5f0f\u95ee\u9898<\/strong><\/h4>\n\n\n\n
    NOW()<\/code> \u8fd4\u56de\u7684\u65f6\u95f4\u683c\u5f0f\u901a\u5e38\u662f YYYY-MM-DD HH:MM:SS<\/code>\u3002\u5982\u679c\u4f60\u53ea\u9700\u8981\u65e5\u671f\u6216\u65f6\u95f4\u7684\u67d0\u4e00\u90e8\u5206\uff0c\u53ef\u4ee5\u4f7f\u7528\u76f8\u5e94\u7684\u65e5\u671f\u65f6\u95f4\u51fd\u6570\u6765\u63d0\u53d6\u3002\u4f8b\u5982\uff1a<\/p>\n\n\n\n
      \n
    • \u83b7\u53d6\u5f53\u524d\u65e5\u671f\uff1a<\/li>\n<\/ul>\n\n\n\n
        SELECT CURDATE();<\/code><\/pre>\n\n\n\n
        \n
      • \u83b7\u53d6\u5f53\u524d\u65f6\u95f4\uff1a<\/li>\n<\/ul>\n\n\n\n
          SELECT CURTIME();<\/code><\/pre>\n\n\n\n
        3.4 NULL<\/code> \u503c\u5904\u7406<\/strong><\/h4>\n\n\n\n
        NOW()<\/code> \u51fd\u6570\u59cb\u7ec8\u8fd4\u56de\u6709\u6548\u7684\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u56e0\u6b64\u4e0d\u4f1a\u8fd4\u56de NULL<\/code>\u3002\u4f46\u5728\u67d0\u4e9b\u5e94\u7528\u4e2d\uff0c\u5982\u679c NOW()<\/code> \u88ab\u5e94\u7528\u4e8e\u67d0\u4e9b\u8ba1\u7b97\u6216\u7ec4\u5408\u64cd\u4f5c\u65f6\uff0c\u53ef\u80fd\u4f1a\u9047\u5230 NULL<\/code> \u503c\u3002\u786e\u4fdd\u4f60\u7684\u6570\u636e\u5e93\u8868\u5b57\u6bb5\u652f\u6301\u65e5\u671f\u7c7b\u578b\uff0c\u4ee5\u907f\u514d\u63d2\u5165 NULL<\/code> \u4f5c\u4e3a\u65e5\u671f\u503c\u3002<\/p>\n\n\n\n
        4. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
          \n
        • NOW()<\/code> \u51fd\u6570\u7528\u4e8e\u8fd4\u56de\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u901a\u5e38\u683c\u5f0f\u4e3a YYYY-MM-DD HH:MM:SS<\/code>\u3002<\/li>\n\n\n\n
        • \u5b83\u53ef\u7528\u4e8e\u8bb0\u5f55\u6570\u636e\u63d2\u5165\u65f6\u95f4\u3001\u67e5\u8be2\u7279\u5b9a\u65e5\u671f\u65f6\u95f4\u7684\u6570\u636e\u7b49\u3002<\/li>\n\n\n\n
        • NOW()<\/code> \u4e0e CURRENT_TIMESTAMP<\/code> \u5e38\u5e38\u53ef\u4ee5\u4e92\u6362\u4f7f\u7528\uff0c\u5177\u4f53\u53d6\u51b3\u4e8e\u6570\u636e\u5e93\u7cfb\u7edf\u3002<\/li>\n\n\n\n
        • \u4f60\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528\u5176\u4ed6\u65e5\u671f\u65f6\u95f4\u51fd\u6570\uff08\u5982 CURDATE()<\/code> \u6216 CURTIME()<\/code>\uff09\u6765\u63d0\u53d6\u65e5\u671f\u6216\u65f6\u95f4\u7684\u67d0\u4e2a\u90e8\u5206\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
          NOW() \u662f SQL \u4e2d\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u7528\u4e8e\u8fd4\u56de\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002\u8be5\u51fd\u6570\u901a\u5e38\u7528\u4e8e\u8bb0\u5f55\u6570\u636e\u63d2\u5165\u6216\u66f4\u65b0\u65f6\u7684\u65f6\u95f4\u6233\uff0c\u6216 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-1745","post","type-post","status-publish","format-standard","hentry","category-sql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1745","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=1745"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1745\/revisions"}],"predecessor-version":[{"id":1746,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1745\/revisions\/1746"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=1745"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=1745"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=1745"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}